Parametric evaluation of microstrip log periodic dipole array antenna using transmission line equivalent circuit

This paper presents the design of a Microstrip Log Periodic Dipole Array (MLPDA) antenna for wireless communication in C band. A simplest structure of the edge fed Microstrip Log Periodic Dipole Array is chosen as base design. The parameters of proposed antenna are identified by investigating the effect of variation in geometrical structure on gain and bandwidth. A scale factor (τ) and a spacing factor (σ) are defined accordingly and imposed, in order to create the variations in these parameters. Complexity of parametric variations involved has been observed through change in bandwidth and realized gain of proposed MPLDA. A transmission line equivalent circuit of the proposed MLPDA is developed to give physical insight of the structure and validation. Log periodic nature of the proposed antenna array is verified by plotting input impedance with logarithm of frequency over the specified range. To validate the results, prototype of proposed antenna is realized in the high frequency laboratory and results are verified with few experimentally measured values.